Chandra X-Ray Observatory image of M42. This X-ray image shows about a thousand
X-ray emitting young stars in the Orion Nebula star cluster. The X rays are produced
in the multimillion degree upper atmospheres of these stars. At a distance of about
1800 light years, this cluster is the closest massive star forming region to Earth.
It is well-known in the night sky because it illuminates the Orion Nebula. The
region shown in this iimage is about 10 light years across. The bright stars in the
center are part of the Trapezium, an association of very young stars with ages less
than a million years. The dark vertical and horizontal lines, and the streaks from
the brightest stars are instrumental effects.

These Chandra images show the central region of the Orion Nebula. Assembled
into a time-lapse movie, these observations show that, over the course of mere
hours, many of the 700 objects in the field appear to "shimmer" or vary, in
X-ray intensity. This flaring behavior appears to be a common characteristic
of young stars. Since the sun formed in a similar region long ago, this
discovery may help us better understand how our solar system formed.

This composite X-ray/optical image was obtained from an
optical Hubble Space Telescope image,
and above Chandra X-ray Observatory image.
It shows the splendid cluster of very young stars emerging from the Orion
Nebula, called the Trapezium Cluster, or the Orion Nebula Cluster.

The bright point-like sources (blue and orange) in this image are the
burgeoning stars captured in X-ray light by a long series of Chandra
observations. These nearly continuous observations, lasting almost 13 days,
allowed astronomers to monitor the activity of Sun-like stars between 1 and
10 million years old. The fledgling stars were seen to flare in their X-ray
intensity much more than our Sun does today. This suggests our Sun had many
violent and energetic outbursts when it was much younger. The wispy filaments
(pink and purple) are clouds of gas and dust as seen by Hubble in optical
light. This gas and dust will one day condense into disks of material from
which future generations of stars will be born.
Credit: X-ray: NASA/CXC/Penn State/E.Feigelson & K.Getman et al.;
Optical: NASA/ESA/STScI/M. Robberto et al.